It has been the object of many horseshoe designers and farriers to provide a horseshoe which is hoof-friendly and which mimics to some extent the movement of a horse's hoof when the horse is walking or running, especially on a hard surface. Various attempts have been made over decades to obviate the rigidity of conventional metallic horseshoes by introducing nonmetallic elements that provide selected degrees of flexibility and resilience.
Prior art includes examples of horseshoe designs incorporating shock absorbing materials (such as for example in U.S. Pat. No. 5,348,098,) either in layers with metallic components or otherwise, without any provision for splaying. There are also examples of flexible horseshoe design in prior art, without any provision for splaying. U.S. Pat. Nos. 6,076,607, 4,513,824, 4,333,532, and 3,628,608 are examples of flexible horseshoes. U.S. Pat. No. 6,810,962 describes a composite horseshoe with a resilient intermediate layer to fill out interspaces between rigid upper and lower parts.
There are also specialty type horseshoe designs in prior art to address specific design needs but not splaying. For example, U.S. Pat. No. 5,727,633 to Ovnicek describes a horseshoe designed for lame horses and has a closed end toe section provided with a concave depression sufficient to avoid contact with the sole of a horse's foot beneath the tip of the coffin bone. The Ovnicek patent describes essentially a “combination” of hoof pad (which is preferably wedge-shaped) with a frog insert and a horseshoe element which raises the horse's heel, to assist a lame horse. It also seems essential in the Ovnicek patent that in order for the “combination” to be effective, the elevated heels and the frog insert must be elongated (vide column 2 of the Ovnicek patent). Notably, the Ovnicek patent provides for no flexibility between left and right wings of the horseshoe, and no such flexibility seems envisaged therein.
U.S. Pat. No. 6,076,607 (Bergeleen) describes a composite horseshoe having left and right body portions and a selectable detachable and interchangeable centerpiece in the toe region, enabling the flexibility of the shoe to be adjusted as desired. The selected centerpiece is provided with tapped holes extending horizontally one on each side and is assembled and held in place by screws inserted in the left and right body portions. The horseshoe in this prior art patent is described as being provided with antisplay flanges which however need to be assembled, thus increasing the cost of using this type of prior art horseshoe.
U.S. Pat. No. 6,082,462 (to Lyden) describes a composite horseshoe which is made of flexible and relatively inflexible materials and which can include a resilient pad for attenuating shock and vibration. U.S. Pat. No. 6,443,232 describes a horseshoe having shock-absorbing qualities, the shoe having a resilient polymer that is sandwiched between metal plates. Yet another horseshoe described as having adherence and a grip over any kind of ground is seen in U.S. Pat. No. 5,988,288 (to Bourdieu), wherein, a rigid core piece may be partially coated with or encased in a rubber compound.
U.S. Patent-publication 2005/0034877 A1 to Bergeleen, dated Feb. 17, 2005 provides a horseshoe that comprises a body made of a molded, flexible polyolefin plastic such as molded ultrahigh molecular weight polyethylene (UHMWPE) or polypropylene, the body having a separate spring metal insert shaped similar to the horseshoe body, enabling the shoe to expand. The horseshoe in the foregoing preliminary publication 2005/0034877 A1 includes a molded-in perforated screen or mesh of steel, spring steel or other metal embedded in the horseshoe-body to add rigidity to the shoe and to constrain the shoe to movement in one plane. The spring metal insert in this prior art composite design is described as sufficiently strong as to pull the UHMWPE body back into its original configuration when weight on the hoof is relieved.
U.S. Pat. No. 985,249 to Butschko (dated Feb. 28, 1911) teaches a horseshoe comprising a flexible metal core and a sectionalized body cast there-around with spaces between sections. Butschko's horseshoe includes a toe-calk and heel calks, which appear to be provided to prevent the horse from slipping and to get a grip. The toe-calk and the heel-calks are in the form of downward projections. U.S. Pat. No. 585,992 (dated Jul. 6, 1897) to Walker teaches a horseshoe wherein the toe or crown portion of the horseshoe has a first transverse slit and further slits extending in lateral directions from the inner end of the first transverse slit. Walker teaches that the slits permit yielding action. Further, U.S. Pat. No. 4,573,538 to Figueras (dated Mar. 4, 1986) teaches a horseshoe comprising a sole plate and having a central hollow zone which can be inflated by injecting (—using a valve—) a compressed fluid. The horseshoe of Figueras is said to provide functions of slip-proofing and damping.
It has however been found that the prior art horseshoe designs which provide resilience may be composite, or use several parts and components, and do not offer simplicity, reliability or cost effectiveness. Those prior art horseshoes which by design use predominantly resilient material, are invariably generally less durable (—short life—) than the conventional rigid metallic designs which might however restrict expansion and thus create increased stress in the hoof and legs of the horse, particularly during racing
Despite the availability of horseshoe designs providing shock absorption, flexibility and such features, there is still a need for a horseshoe design which is characterized by simplicity, economy and including controlled splaying without any need for a multiplicity of components and without the need for assembly of parts. The present invention intends to obviate complexity and certain less desirable aspects of prior art horseshoe design and provides a relatively less expensive and very simple design which aims at causing and allowing the much desired splaying for mitigating hoof-stress particularly during racing. The present invention also aims at providing structural features in the horseshoe to promote hoof-comfort and consequent hoof-wall-growth and hoof structure regeneration.